1. Technical Field
The present invention relates to a suction device and a suction system which have a plurality of head caps capable of closely contacting with and moving away from corresponding nozzle surfaces of a plurality of inkjet functional liquid droplet ejection heads, and a liquid droplet ejection apparatus having the device or the system, as well as an electro-optical apparatus and a manufacturing method thereof.
2. Related Art
It is known that suction systems have seven suction units (suction devices) on which twelve head caps are mounted, corresponding to seven carriage units on which twelve functional liquid droplet ejection heads are mounted (JP-A-2005-254798).
Each suction device (suction unit) includes a cap unit on which twelve head caps are mounted on a cap plate, a contacting/separating mechanism that contacts and moves the twelve head caps with and away from twelve functional liquid droplet ejection heads by using the cap plate, a waste liquid tank communicating to the twelve head caps, an ejector that connects its secondary side to the waste liquid tank in order to apply suction pressure to the tank, and a suction channel that connects the twelve head caps to the waste liquid tank.
When compressed air is introduced to a primary side of the ejector to drive the ejector while the head caps are closely contacted with their corresponding functional liquid droplet ejection heads, inside the waste tank and the suction channel is under negative pressure so that the functional liquid is sucked from the twelve functional liquid droplet ejection heads via the twelve head caps. The head caps are slightly spaced apart from the functional liquid droplet ejection heads, and thereafter the ejector is driven while the functional liquid droplet ejection heads are subjected to ejection for maintenance (flushing), whereby ejection for maintenance can be undergone. As such, the above two functions allow the function of the twelve functional liquid droplet ejection heads to be maintained and recovered.
Each of the seven suction devices (suction units) is independently provided in such related-art suction systems, and the waste liquid tank and the ejector are independently provided. This arrangement disadvantageously decreases space efficiency and makes the structure complex. In this case, such a disadvantage can be overcome if the seven suction devices, the waste liquid tank, and the ejector are integrated into a unit.
However, suction pressure for sucking functional liquid from a number of ejection nozzles is higher than suction pressure for sucking functional liquid ejected from the head caps. Thus, if an operation method is taken in which a suction device performing suction and a suction device undergoing ejection for maintenance are provided together, it is impossible to conduct both operations with the above configuration.